JPH01275685A - Adhesive composition - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition capable of firmly bonding a polyolefin material, which is difficult to bond, without any pretreatment, by incorporating a chloroprene rubber, a polyisocyanate, and a halogenating agent into a polyester urethane containing isocyanate groups. CONSTITUTION:An adhesive for a polyolefin material is prepared by mixing a polyester urethane (A) having isocyanate groups, e.g., a reaction product of a prepolymer prepared 4,4'-diphenylmethane diisocyanate and a polybutylene adipate with a chain extender comprising, e.g., butylene glycol; a chloroprene rubber (B), the weight ratio of A to B being 2-98:98-2; a polyisocyanate (C) in an amount of 0.1-30pts.wt. based 100pts.wt. solids of A+B; and a halogenating agent (D) in an amount of 0.002-20pts.wt. based on 100pts.wt. solids of A.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is applicable to adhesion of difficult-to-adhesion polyolefin materials used, for example, as automobile parts, adhesion of materials for electrostatic flocking, rubber products, and synthetic resins. The present invention relates to an adhesive composition used for adhering products.

[Conventional technology]

Conventionally, methods for adhering polyolefin-based materials such as polypropylene, which are difficult to adhere, include a method in which an adhesive is applied after surface treatment with a primer such as chloroprene rubber, and a method in which an adhesive is applied after a corona discharge treatment. It is being

[Problem to be solved by the invention]

However, these bonding methods require pretreatment such as primer treatment and corona discharge treatment before bonding polyolefin materials, which not only increases the number of steps and has poor workability, but also has low adhesive strength. there were.

The purpose of the present invention is to solve the above-mentioned conventional problems and to provide an adhesive composition that can be bonded to polyolefin materials that are difficult to bond without pretreatment and that has high adhesive strength. be.

[Means to solve the problem]

In order to achieve the above object, the present invention employs a method of forming an adhesive composition from polyester urethane having an isocyanate group (-NCO), chloroprene rubber, polyisocyanate, and a halogenating agent.

Polyester urethane is composed of polyisocyanate and polyester polyol, and polyisocyanate is a compound having a plurality of isocyanate groups, such as 2,4-tolylene diisocyanate (TDI).
, 65/35 (ratio of 2,4-tolylene diisocyanate and 2.6-)lylene diisocyanate, the same applies hereinafter) tolylene diisocyanate, 80/20') lylene diisocyanate, 1.5-naphthalene diisocyanate (NDI), 4 .4'-diphenylmethane diisocyanate (MDI), dianisidine diisocyanate, tridene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate (XDI), metaxylene diisocyanate, 1,6-hexamethylene diisocyanate (1°6HMDI), hydrogenated 4, 4'-diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, hydrogenated 2,4-)lylene diisocyanate, hydrogenated 65/35) lylene diisocyanate, hydrogenated 80/2
0) Rylene diisocyanate, isophorone diisocyanate (I PD I), etc. can be used.

In addition to the above-mentioned polyisocyanates, the polyisocyanates to be blended include trifunctional isocyanate 4
, 4',4''-triphenylmethane triisocyanate (TPMT), ) lith(P-isocyanate phenyl) thiophosphate (TIPP), etc. A good range is 0.1 to 30 parts by weight based on 100 parts by weight of the solid content of the urethane and chloroprene rubber.This is because if the blending ratio is less than 0.1 parts by weight, the improvement in adhesive strength will be small (.30 parts by weight). This is because if the adhesive strength exceeds 100 mm, no improvement in adhesive strength can be expected.

Polyester polyols include polybutylene adibe) (PBA) and polyethylene butylene adibe)
(PEBA), polyethylene adipate (PEA)
, polyethylene sebacate <PE5e), etc. can be used.

Further, as a halogenating agent, for example, as an alkyl hypohalide, t-butyl hypochloride (t-BH
C) As hypohalites, sodium hypochlorite and potassium hypochlorite; as compounds having a -CONX- bond in the molecule, N-bromosuccinimide (NBS);
I), isocyanuric acid trichloride (TCIA), isocyanuric dichloride M (DiCIA), and others such as antimony pentafluoride, a mixed solution consisting of sulfur fluoride and bromine, etc. can be used, but among these, alkyl hypohalides, Hypohalites or compounds having a -CONX- bond in the molecule are preferred. The blending ratio of the halogenating agent is preferably in the range of 0.002 to 20 parts by weight based on 100 parts by weight of the solid content of the polyester urethane. This is because if the blending ratio is less than 0.002 parts by weight, the degree of chlorination will be small, resulting in little improvement in adhesive strength, and if it exceeds 20 parts by weight, the stability of the adhesive composition will deteriorate.

In addition, the blending ratio of chloroprene rubber is polyester urethane/chloroprene rubber = 2 to 98/9 by weight.
It can be set arbitrarily, such as from 8 to 2.

Incidentally, a chain extender, a solvent, and a phenol resin may be used if desired, and examples of the chain extender include butylene glycol (BG), 1,6-hexanediol (1,6HD
), ethylene glycol (EG), propylene glycol, butanediol 1°4, butanediol 1,3,
One or a mixture of two or more of butanediol 2.3, diethylene glycol, dipropylene glycol, triethylene glycol, bentanediol 1,5, hexanediol 1,6, neopentyl glycol, etc. can be used.

Examples of the solvent include aliphatic hydrocarbons such as n-hexane, n-hebutane, and n-octane; alicyclic hydrocarbons such as cyclohexane and cyclooctane; aromatic hydrocarbons such as benzene, ethylbenzene, toluene, xylene, Ketones: acetone, methyl ethyl ketone, ethyl propyl ketone, methyl butyl ketone; ethers: tetrahydrofuran; acetic acid esters: methyl acetate, ethyl acetate, isopropyl acetate; halogenated hydrocarbons: methylene chloride, 1.1.1
-)IJ Chlorethane, trichloroethylene, dimethyl sulfoxide (DMSO), dimethyl formamide, etc. are mentioned.

These solvents may be used alone or as a mixed solvent of two or more, and the blending ratio of the adhesive composition and these solvents may also be set arbitrarily.

Examples of phenolic resins include novolak-type alkylphenols such as Tamanol 510, Tamanol 515, Tamanol 803, and Tamanol 5 manufactured by Arakawa Chemical Co., Ltd.
26, Tamanol 528, resol type alkylphenol such as Damanol 520S, Tamanol 521, Kumanol 573, Tamanol 577, Tamanol 586, and terpene type alkylphenol such as Damanol 803 can be used.

[Effect]

According to the above configuration, even if an adhesive composition is applied directly between two polyolefin materials that are difficult to bond to each other without any pretreatment, these polyolefin materials are firmly adhered.

〔Example〕

Examples using the adhesive composition of the present invention will be described below in comparison with comparative examples.

First, a polyester urethane having isocyanate groups was synthesized at the following blending ratio.

Polyester urethane■ PBA (number average molecular weight 5
00) 66.56 parts by weight were mixed in trichlorethylene and reacted at 80° C. for 3 hours in a dry nitrogen gas atmosphere to synthesize a polyester-based urethane prepolymer. Thereafter, 40 parts by weight of EC20 was added to this polyester urethane prepolymer and reacted at 80° C. for 20 minutes to synthesize a polyester urethane. The obtained polyester urethane had a solid content of 25% and a trichlorethylene content of 75%.

Polyester urethane ■ 266.31 parts by weight of PEBA (number average molecular weight 2000) was mixed with 100 parts by weight of MD I in trichlorethylene, and the mixture was reacted at 80°C for 3 hours in a dry nitrogen gas atmosphere to form a polyester urethane preform. The polymer was synthesized. Then, 26.76 parts by weight of 1.6HD was added to this polyester-based urethane prepolymer and heated to 80°C.
The mixture was reacted for 20 minutes to synthesize polyester urethane. The obtained polyester urethane had a solid content of 25% and a trichlorethylene content of 75%.

Polyester urethane■ PEA (number average molecular weight 10
00) 191.94 parts by weight were mixed in trichlorethylene and reacted at 80° C. for 3 hours in a dry nitrogen gas atmosphere to synthesize a polyester-based urethane prepolymer. Thereafter, EC44.09 parts by weight was added to this polyester-based urethane prepolymer and reacted at 80°C for 20 minutes to synthesize a polyester-based urethane. The obtained polyester urethane had a solid content of 25% and a trichlorethylene content of 75%.

Polyester urethane ■ 100 parts by weight of 1.6HMDI and 99.10 parts by weight of PE5e (number average molecular weight 1000) were mixed in trichlorethylene and reacted at 80°C for 3 hours in a dry nitrogen gas atmosphere to form a polyester urethane preform. The polymer was synthesized. Thereafter, 28.92 parts by weight of EC was added to this polyester-based urethane prepolymer and
A polyester-based urethane was synthesized by a minute reaction. The obtained polyester urethane had a solid content of 25% and a trichlorethylene content of 75%.

Polyester urethane■ PEA (number average molecular weight 1
000) were mixed in trichlorethylene and reacted at 80° C. for 3 hours in a dry nitrogen gas atmosphere to synthesize a polyester-based urethane prepolymer. Thereafter, 5.79 parts by weight of EC was added to this polyester urethane prepolymer and reacted at 80° C. for 20 minutes to synthesize a polyester urethane. The obtained polyester urethane had a solid content of 25% and a trichlorethylene content of 75%.

Next, for the solid content of polyester urethane shown in these ■～■, chloroprene rubber, polyisocyanate,
An adhesive composition was obtained by blending a halogenating agent and a phenol resin in predetermined proportions.

(Example 1) An adhesive composition was obtained by blending 2 parts by weight of chloroprene rubber (CR), 1 part by weight of MD I0. Ta.

(Example 2) CR2 for 80 parts by weight of polyester urethane
0 parts by weight, 30 parts by weight of MD I, and 1 part by weight of t-BHC to obtain an adhesive composition.

(Example 3) CR4
0 parts by weight, XDIIO parts by weight, and NB511 parts by weight were blended to obtain an adhesive composition.

(Example 4) CR6 to 40 parts by weight of polyester urethane
0 parts by weight, TDIIO and 1 part by weight were blended to obtain an adhesive composition.

(Example 5) CR8 for 20 parts by weight of polyester urethane (1)
0 parts by weight, IPDIIO and 20 parts by weight were blended to obtain an adhesive composition.

(Example 6) CR98 to 2 parts by weight of polyester urethane (2)
Parts by weight of TPMTIO and 1 part by weight of TCIA were blended to obtain an adhesive composition.

(Example 7) CR4 for 60 parts by weight of polyester urethane
0 parts by weight, 710 parts by weight of TPM, 1 part by weight of TCIA, and 1 part by weight of Tamanol 520S were blended to obtain an adhesive composition.

(Example 8) CR4 for 60 parts by weight of polyester urethane (1)
0 parts by weight, 10 parts by weight of TlPP, 1 part by weight of TCIA, and 20 parts by weight of Tamanol 803 were blended to obtain an adhesive composition.

(Example 9) CR4 for 60 parts by weight of polyester urethane
0 parts by weight of TlPPl, 1 part by weight of TCIA, and 10 parts by weight of Tamanol 340 were blended to obtain an adhesive composition.

Next, in order to examine the adhesive strength of the adhesive composition thus obtained, the following moisture peel test was conducted.

The test pieces used for this moisture peeling test were two test pieces made of 5x polyethylene foam, the adhesive composition was applied to an adhesion area of 25x25n+, and the solvent was evaporated by heating at 100°C for 2 minutes. ,+r/cj for lamination 5
The resulting test piece was left at 50°C and 98% relative humidity for 200 hours.
Thereafter, it was pulled at a tensile speed of 50 mm/min and its moisture resistant peel strength was measured.

The results are shown in Table-1.

Table 1 Note that in the column of moisture resistant peel strength in Table 1, * indicates failure of the polyethylene foam as the adherend.

Moreover, Comparative Examples 1 to 3 were obtained using the following formulations.

(Comparative Example 1) Adhesive composition obtained only from the polyester urethane (1).

(Comparative Example 2) 50 parts by weight of MD I, TC for 100 parts by weight of CR
An adhesive composition obtained by blending 1 part by weight of IA.

(Comparative Example 3) CR4 for 60 parts by weight of polyester urethane
An adhesive composition obtained by blending 0 parts by weight and MDIIO parts by weight.

As is clear from Table 1, the adhesive composition containing isocyanate group-containing polyester urethane, chloroprene rubber, polyisocyanate, and halogenating agent has a foam that is 5 times larger than that of polyethylene as the adherend. It can be seen that the greater the peel strength, the greater the peel strength.

The reason why the adhesive composition of the present invention exhibits such excellent adhesive strength is that the halogen in the halogenating agent halogenates the non-polar polyolefin of the adherend, and the polyester base in the adhesive composition By halogenating the urethane, the intermolecular force between the two is increased, and the peel strength is improved by the use of flexible and elastic chloroprene rubber. This is thought to be due to a synergistic effect that further improves the adhesive strength.

On the other hand, as shown in Comparative Examples 1 to 3, when any of the aforementioned polyester urethane, chloroprene rubber, polyisocyanate, and halogenating agent is not blended, the stability of the adhesive composition is poor. It can be seen that the adhesive strength is extremely low.

Now, in this example, not only can polyethylenes, which are difficult to adhere to each other, be easily adhered to each other without using a conventionally used primer, but also the adhesive strength is extremely high. Therefore, the adhesive composition of this example can be suitably used, for example, in automobile moldings, substrates for electrostatic flocking, interior parts, rubber products, etc. in which polyolefin materials are used.

〔Effect of the invention〕

As detailed above, the adhesive composition of the present invention not only enables adhesion without pretreatment to polyolefin materials that are particularly difficult to adhere to, but also has an excellent adhesive composition with extremely high adhesive strength. be effective.

Claims (1)

[Claims] 1. An adhesive composition comprising a polyester urethane having an isocyanate group (-NCO), chloroprene rubber, a polyisocyanate, and a halogenating agent.